Excess air cycle internal combustion engine



Oct. 1, 1957 E. A. VON SEGGERN ETAL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE Filed Jan. 16, 1956 6Sheets-Sheet 1 NM V 5 06 N 6 e was m V N fir w w 1957 E. A. VON SEGGERNEI'AL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE Filed Jan. 16, 1956 6Sheets-Sheet 2 INVENTORJ Ems/557,4 VaA/jsaanz/v flavev E. Vow 56666N '44. Q I v Oct. 1, 1957 E. A. VON SEGGERN ETAL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE 6 Sheets-Sheet 3 Filed Jan.16, 1956 INVENTORJ FAA/1724, Kw55662- He/vzv E. VaA/SEaaaW BY 4 a!Arron/v69 Oct. 1, 1957 E. A. VON SEGGERN ETAL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE 6 Sheets-Sheet 4 Filed Jan.16, 1956 INVENTORS i/zA/esr ,4 Kw 566654 Ham: v 5 Kw .fi'zaauv fi rra/evf X Oct. 1, 1957 E. A. VON SEGGERN ETAL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE 6 Sheets-Sheet 5 Filed Jan.16, 1956 INVENTORS Elm 557A Vm/iaamx' HEN/2v E. VON'SEGEB/V Oct. 1, 1957E. A. VON SEGGERN EIAL 2,808,037

EXCESS AIR CYCLE INTERNAL COMBUSTION ENGINE Filed Jan. 16, 1956 eSheets-Sheet e INVENTORS [man A wA d'saauy BY HiNlY E. Vo-5ea6s2- UnitedStates Patent EXCESS AIR CYCLE INTERNAL COMBUSTIGN ENGIWE Ernest A.'vonSeggern, Burbank, and Henry von Seggern, Escondido, Calif.

Application January 16, 1956, Serial No. 559,261

37 Claims. -(Cl. 12332) This invention relates to combustion chambersfor internal combustion engines, and in particular to chambers which aredesigned to operate with excess air in both high and low compressionengines, and with either spark ignition or self ignition. Fuels such asgasoline, distillate, fuel oil, JP (jet propulsion) fuel, .etc., aresuitable for use in the combustion chambers and are burned at allcompressions without detonation without regard to the octane or cetenenumber.

It is a general object of the invention to provide a combustion chamberof the type described in which fuel is burned which contains noadditives of any type, and in which a combustion is obtained which isclean, fast, quiet and odorless. Another object is to provide acombustion chamber in which all types of fuel may be burned withoutforming gum or deposits or without diluting the lubricating oil withunburned fuel or sludge.

More specific objects include the provision of: a c0mbustion chamberwhich operates with full excess air at part loads, particularly in lowcompression engines, to obtain the excellent part load thermalefliciency characteristic of high compression excess air cycle engines;a combustion chamber in which all types of fuel maybe burned, and whichreceives its fuel from a low pressure, non-atomizing injection systemwhose timing relative to the engine cycle is non-critical; a combustionchamber in which all types of fuel may be ignited by a spark plug or aspecial low temperature low pressure self-ignition system; and acombustion chamber in which combustion is inherently stable and does notdepend for its eflicient operation upon critical adjustments, but iscontrolled principally by means of air flows which are produced by meansof fixed structure which does not change with time.

Other general objects and features of the invention as well as specialobjects and features applicable to specific forms will be described inthe specification in conjunction with the description of the specificforms shown therein.

The combustion chambers by means of which the foregoing objects areattained make use of a flame induced fuel vaporization method in whichan ignition flame progressively'vaporizes a charge of pre-heated liquidfuel, progressively forms a localized fuel-air mixture therefrom in thepresence of excess air, and fires the fuel mixture as it is formed. Thecombustion chambers also make use of an ignition flame which is obtainedfrom a localized charge of cool, vaporized fuel pre-mixed with air instoichiometric proportions and surrounded by excess air, which joins inthe reaction after the initial charge has been ignited and partiallyburned and the air has become heated.

Additional features of the combustion chambers will be described inconjunction with a description of the engine and its mode of operation.In the accompanying drawings showing typical illustrative embodiments ofthe broad invention: 7

Figure 1 is a section of a preferred form of sparkignition engine takenalong the broken line 1-1 of Figure 2,808,037 Patented Oct. 1, 1957 2 2in vertical planes parallel to the crank shaft of amultiplecylinder-'in-line engine;

Figure 2 is a horizontal section taken along the broken line 22 ofFigure 1;

Figure 3 is a vertical section taken along the broken line 33 of Figure'2;

Figure 4 is a horizontal section taken along the broken line 44 ofFigure 1 showing the passage from the cylinder, the connecting zone, thecombustion chamber, and the ignition chamber;

Figure 5 is a dimetric projection, partially cut away, showing thecylinder head viewed from the cylinder side of the engine, and showingthe air flows in the head during the compression cycle;

Figure 6 is a dimetric projection, partially cut away, showing theconnecting zone with fuel vaporization means for producing fuel chargesfor the ignition chamber;

Figure 7 is a vertical section taken along the broken line '7--7 ofFigure 4 showing flow dividing means at the junction of the connectingzone and the passage from the cylinder;

Figure 8 is a dimetric projection, partially cut away, showing theignition chamber with an alternate type of air cell which may be appliedto the engine;

Figure 9 is a vertical section of a second form of sparkignition enginetaken along the broken line 9- 9 of Figure 10;

Figure 10 is a horizontal section taken along the broken line 10--10 ofFigure 9;

Figure 11 is a vertical section of a low pressure selfignition typeengine taken along the broken line 11-11 of Figure 12;

Figure 12 is a horizontal section taken along the line 1212 of Figure11;

Figure 13 is a section taken along the broken line 13-13 of Figure 11showing the gas flows in the ignition chamber charging passage;

Figure 14 is a vertical section of an engine which operates on the Ottocycle with throttled air supply, taken along the broken line 14-14 ofFigure 15; and

Figure l5.is a horizontal section of the engine taken along the brokenline 1515 of Figure 14.

The combustion chambers will be described :as they operate whenincorporated in four-cycle, water-cooled engines, but it will be evidentthat other cooling means can be used and that the chambers can also beapplied to any type of engine employing a cyclic process of compression,combustion, and expansion, such as the two cycle engine and those typesof engines which employ no mechanical piston at all but obtaincompression and expansion by means of pressure waves in the workingfluid. The chambers may also be incorporated in those types of burnerswhich do not operate with intermittent combustion but maintain a steadyflame in the combustion chamber, because incremental portions of thefuel and working fluid therein pass through the same sequence of stepsas take place in a piston engine.

A preferred form of spark ignition of conventional four cycle, watercooled, valve-in-head design is shown in Figures 1 to 8, inclusive. Acylinder 10 with reciprocating piston 11 therein has a cylinder head 12fastened onto its upper end and both cylinder and cylinder head arewater cooled by means of a jacket 13. An inlet valve 14 and an exhaustvalve (not shown) are located in head 12 above said cylinder, and areoperated in the conventional manner by the usual mechanism (not shown).An auxiliary head 15, including a water jacket 16, is fastened to theside of head 12, and gives access, when removed, to combustion spaceseparate from that O enclosed by cylinder 10 and piston 11.

Formed within heads 12 and 15 are a combustion cham ber 17, an ignitionchamber 18, and a T shaped connecting zone 19 which includes a legsegment 20 and a cross-arm 21 normal thereto. One end of the cross-armcommunicates with combustion chamber 17 through junctural passage 22 andforms a communicating zone between the connecting Zone and thecombustion chamber. The other end of the cross-arm communicates withignition chamber 18 through passage 23, and this forms, with saidjunctural passage, a substantially straight, continuous passage from theignition chamber to the combustion chamber. The .leg segment 20communicates with cylinder 10 through a curved passage 24.

A spark plug 25 is screwed into the threaded opening 26 of the ignitionchamber 18 and a fuel injector 27, mounted horizontally in the auxiliaryhead 15, and substantially normal to passage 23, is clamped in place bymeans of a threaded nut 28. A conventional fuel injection pump (notshown) delivers fuel to said injector through a fuel line 29. Fuelnozzle 30 in the end of said injector projects into the passage 23 andhas a single orifice through which the fuel is delivered in anunatomized stream 32 onto a fuel receiving surface 33. The injected fuelimpinges obliquely on this fuel receiving surface and spreads out intoan elongated fuel body extending from the point of impingement 34 towardthe combustion chamber for a variable distance, proportional to thequantity of fuel injected. At no load idle operation the fuel body isindicated by the outline 35, while at full load it is indicatedgenerally by the outline 36. The fuel is injected generally. during theintake stroke, but injection may continue somewhat into the compressionstroke. Since the engine operates at all times with a full unthrottledcharge of air, the power output is controlled simply by varying thequantity of fuel injected.

During the compression cycle, air from cylinder 10 is displaced intopassage 24 in a stream 37 as shown in Figures 4,5, 6 and 7. At atangential juncture of passage 24 with leg segment 20 (see Figs. 4, 5and 7) stream 37 is divided by flow dividing means 38 describedhereinafter, into an upper branch stream 39 and a lower branch stream40, which charge the combustion chamber 17 and the ignition chamber 18,respectively. Upper branch stream 39 spreads out fan-wise in zone 19(see Fig. 4) into a pair of streams 41 and 42, of which stream 41 passesdirectly into combustion chamber. 17, while stream 42 impingessubstantially normally against side wall 43. After impingement, stream42 divides into a first stream 44 flowing into combustion chamber 17, asecond stream 45 flowing downwardly (see Fig. 5) along wall 43, and athird stream 46 flowing horizontally along wall 43 into the cup shapedcavity 47 directly above the ignition chamber passage 23.

Simultaneously with the above, lower branch stream 40 flows into zone19, impinges substantially normally against the bottom of side wall 43(see Fig. 5), and divides into three streams 48, 49 and 52. Stream 48flows toward the combustion chamber 17, while stream 49 flows upwardly,meets and joins stream 45, and combines therewith to form new stream 50.Stream 5% flows away from side Wall 43 and crosses the connecting zoneto the opposite wall 51 (see Figs. 1 and 4) where it is turned and flowstoward the combustion chamber. The third stream 52 (Figs. 5 and 6) turnstoward the ignition chamber passage 23, and upper stream 46,,circulatingin cavity 47, flows downwardly in a descending spiral 53 (Fig. 6) abouta vertical axis54, and meets stream 52. Stream 52 also circulates aboutaxis 54 and impinges on side wall 55 (Fig. 4) directly below cavity 47,where it is divided. A branch 56 continues to circulate and the otherbranch stream 57 passes up the passage 23 into the ignition chamber. 7

In the ignition chamber, stream 57 circulates around the annular grooveor channel 58 in a stream 59, and then passes in a spiral flow 60 up theside walls 61 (Fig. 5). At the spark plug 25 the air converges in aspiral stream 62, flows axially down the center of said chamber in astream 63, and recirculates with the entering stream 57.

Stream 41, which flows directly into the combustion chamber 17, impingessubstantially normally on a back wall thereof in a zone 64, and dividesin a fan-like manner into two new streams. One stream flows generallydownward in a spiral 65, and the other stream 66 flows directly upwardto the top 67 of chamber 17. Here it turns and flows across the top andcomes down again on the opposite sidewall 63 to join with stream in aspiral flow converging toward the center 69 of the bottom wall 70 ofchamber 17. Stream 44, which flows toward chamber 17 through juncturalpassage 22, is deflected downwardly along side Wall 71 of chamber 17 bybafiie 72 (Fig. 6) and also flows in a spiral toward the center ofbottom wall 70. The three streams 44, 65 and 66 combine to produce auniformly converging spiral flow.

The air stream 40, in flowing along the bottom of the connecting zone19, cuts directly across the fuel body which has been injected onto fuelreceiving surface 33, and separates the fuel along a line 73 whichcoincides with the end of the idle fuel charge remote from the point offuel impingement. The quantity of fuel on the ignition chamber side ofthis dividing line is always substantially uniform, while the quantityof fuel on the combustion chamber side is variable. The fixed quantityof fuel is repeatedly swept over by the circulating stream 56, and thevapors produced are carried into the ignition chamber 18 by vaporcarrier stream 57. The quantity of vaporized fuel added to the full aircharge in the ignition chamber is fixed so as to produce aspark-ignitable fuel-air mixture having substantially stoichiometricproportions, and the size of the ignition chamber is made such that thepower produced by this charge is sufficient by itself to idle theengine.

The variable quantity of fuel in chamber 17 is held in the liquid stateduring the entire compression cycle prior to ignition. The full loadfuel charges deposited on bottom wall 70 are retained in the liquidstate by means of the converging streams 44, 65 and 66 which flow at lowvelocity over the fuel and tend to concentrate it in the localizedcentral area 69. The light load fuel charges extend essentially onlyonto the bottom wall area 74 of junctural passage 22 and the streams 48and 50 which flow through this passage into the combustion chamber aresufficiently mild and diffused not to appreciably vaporize the fuelretained therein.

Shortly before top dead center, the prepared fuel-air mixture inignition chamber 18 is ignited by spark plug 25, and the burning chargeflows down passage 23, through connecting zone'19, and into chamber 17in a flow 76, as shown in Fig. l. The flaming gases bear forcefullyagainst the retained liquid fuel charge on the fuel receiving andretaining surface 33 and vaporize and ignite a substantial portionthereof. Theexpanding gases from the resulting combustion in chamber 17flow in a line 77 (Fig. 1) through the connecting zone 19 and passage 24into clearance space 78 provided above the piston 11. Flow 77 isdeflected against surface 33 by baffle 79 (Figs. 1, 2 and 5), andflaming gases sweep a second time over any fuel still retained thereon.The final combustion is obtained by means of excess air in the stream 77and by air in the space 78.

The actual combustion process as carried out in the preferred embodimentof the invention is more complex than is indicated by the foregoingcycle of operation, and will be described in more detail in conjunctionwith a description of the air charging means, excess air supply means,and fuel charge preparation means which are located in the connectingzone 19, shown in section in Figure 6. The connecting zone is one of themost important elements in the combustion system, both because of themany functions that are performed therein, and because it is the commonelement onto which the ignition chamber, the combustion chamber and theengine cylinder are joined to form an operative structure.

The air charging means in said connecting zone supply the ignitionchamber and combustion chamber with air during the compression cycie,and also maintain the ratio of residual exhaust gases to new air in eachchamber equal to that ratio inherently fixed by the compression ratio ofthe engine. The desired air distribution is obtained by means of aseries of four air pressure zones located between the combustion chamberand the ignition chamber that act as gas flow barriers, and prevent theflow of residual gases from one chamber to the other during the chargingcycle. The pressure zones are formed by means of diffused air which isobtained in flow dividing means 38.

The means 38 consist of passage 24 in tangential juncture with the legsegment of zone 19 and a circumferential groove 81 which begins at point82 (Figs. 5 and 7) near the top of said means and extends downwardly ina twisted spiral to a point below passage 24 behind lip or edge 83,where it terminates by blending into leg segment 20. Stream 37 isdirected by passage 24 to flow substantially normally onto the back wall84 of groove 81 and the air in the groove is thereby diffused and formsstream 40. The capacity of groove 81 is so limited that stream 37 isdivided into the stream 40, which fills the groove, and the stream 39,which passes through, inside the loop of the groove, and flows withoutdiffusion directly into chamber 17.

The first pressure zone barrier is located directly in front of theignition chamber charging passage 23, where diffused stream 40 cutsacross the connecting zone and impinges on side wall 43. The body ofdiffused air which forms said barrier is maintained in front of theignition chamber charging passage during the entire compression cycle upto the time of ignition, and the air for charging the ignition chamberis drawn from this source.

The second pressure zone barrier is located in the junctural passage 22and is maintained there by means of diffused streams 48 and 50 whichflow at a low velocity toward chamber 17 and purge the passage ofresidual gases.

The third pressure zone barrier is located between the first barrier andpassage 23, and is formed by streams 53 and 56 which circulate directlyin front of passage 23 about a vertical axis of rotation 54 whichterminates against the top and bottom walls 85 and 86 of zone 19. Thethird barrier is designed to cut off any streams of residual gases whichmay penetrate the first and second barriers, particularly along thehorizontal axes about which streams 40 and 50 tend to circulate. Theimportant feature of the third barrier ,is that the axis of rotation ofthe circulating air therein is normal to the axes of rotation of the airin the first and second barriers and thereby any axial continuitythrough the system is cut off.

The fourth pressure zone barrier is located in passage 23, and is formedby the pressure induced displacement flow 57 which is the vapor-carrierstream that charges the ignition chamber. This diffused flow, contraryto a jetted, high velocity stream, completely .fills the passage 23, andblocks the entry of residual gases.

The proper functioning of the pressure zone barriers is obtained largelythrough the design of side wall 43 of zone 19. 'Both the upper stream 42and lower stream 40 impinge substantially normally on thiswall wherethey are diffused and divided into three diverging streams each. Inaddition to this, a rib or cusp 87 (.Figs. 6 and 8) is provided on wall43 to fix the position where components 45 and 59 impinge on each' otherand combine to form stream 50. The cusp is also used to establish thedirection of flow of said stream away from said Wall.

The system of diffused air barriers in the connecting zone hasadditional uses besides preventing the flow of residual gases from thecombustion chamber into the ignition chamber. During the compressioncycle the eneu'lating stream 56, which forms part of the third barrier,

vaporizes the fuel for the ignition chamber, and it has sufficientenergy to build up a concentrated mixture of cool vapors because it isdriven by streams 40 and 46, which drive the vaporizing stream but donot themselves sweep over the fuel. The diff-used vapor-carrier stream57 does not have enough energy and velocity by itself to vaporize thefuel and form a cool vapor charge, and for this reason it is importantto have a fuel vaporizer separate from the ignition chamber in aposition Where forces external to the ignition chamber can be applied toit.

The four air barriers also provide a continuous path of diffused airfrom the ignition chamber to the combustion chamber through which theignition flame may easily pass in an undispersed stream when ignitionoccurs. The ignition flame must have an unrestricted path into thecombustion chamber in order to effectively induce combustion therein andinterception with the high velocity charging stream 41 is thereforecarefully avoided.

It is a unique feature of the connecting zone, that within a single openpassage, an air flow system is established which prevents circulation ofresidual gases, forcefully vaporizes a fuel charge for the ignitionchamber, and provides a free path for the ignition flame to fire throughinto the combustion chamber.

The excess air supply means in the connecting zone deliver excess air tothe ignition chamber during the charging cycle, and in order not tointerfere with ignition, the air is localized in zones away from thespark plug points .at the time of ignition. This air is provided tomaintain the ignition chamber and spark plug in a clean condition at alltimes; to oxidize residual fuel on the fuel receiving surface forproducing ignitable fuel vapors and for maintaining said surface in astable condition; to promote ignition and combustion of the fuel inchamber 17; and to produce a clean and odorless combustion.

Three different methods for obtaining the excess air are provided, andthey may be used either singly or in combination. In the firstmethod,-the excess air is obtained by means of a process which makes useof the difference in the rate of fuel vaporization at the beginning andend of the compression cycle. The vaporizing stream 56 is capable ofvaporizing more fuel than is supplied to the fuel receiving surface 33,and therefore, being in limited supply, the bulk ofthe fuel is vaporizedearly in the vaporizing cycle. This results in the delivery of a morethan stoichiornetric mixture to the ignition chamber at the beginning ofthe charging cycle, followed by a leaner and leaner mixture toward theend.

As the fuel-air charge enters the ignition chamber -it flows firstaround the annulus 58, then passes in a spiral flow 60 up the side walls61, and finally flows in a converging spiral 62 toward the spark plugpoints 90. This carries the initially rich portion of the ignitioncharge up to the spark plug points where it is ignited, While the leanerafter-portion fills the annular groove 58 and follows up the side walls61. The rich portion becomes distributed along the length axis ofchamber 1.8

in an axial stream 63, while the surrounding leaner zone extends up eveninto the annular space 91 of the spark plug, where the excess airpromotes cleaning of the insulator.

When the spark plug ignites the central charge in the ignition chamber,combustion is initiated in a mixture of near stoichiometric proportionswhich burns rapidly. The charge is, however, surrounded by excess air,and after this air is heated by the central combustion it mixes with theburning gases and joins therewith to produce an exceptionally cleanburning flame. The excess air is added to the flame at near peakpressures and temperatures when it is most effective, and when it doesnot interfere with ignition or the initial propagation of the flame.

The second method of supplying excess air to the ignition chamber isbased on the fact that the combined flows .of air stream 53 andvapor-carrier stream 57 charge the ignition chamber, and by increasingthe strength of air stream 5.? relative to vapor-carrier stream 57during the compression cycle, the ignition chamber is supplied With arelative excess of air toward the end of its charging period. Therelative strength of streams 53 and 57 change durmg the compressioncycle because they originate in streams 39 and 40 respectively, whichlatter have their relative strength changed in passing through flowdividing means 38. Stream 39 flows substantially without restrictionthrough said means While stream 40 has its flow re stricted and limitedtherein, particularly at high velocities. The loss of flow is caused byfrictional resistance in groove 81 and by branching into a separatestream 92 formed by aspiration at the lip or edge 83. Assuming streams39 and 40 to be of equal strength at the beginning of the compressionstroke when velocities are low, it is evident that stream 40 will becomesomewhat weaker relatlve to stream 39 as velocities increase, and therespective branch streams 57 and 53 will alsochange in a correspondmgmanner.

The stream 92, which is formed by aspiration at the edge 83 and becomesdiffused thereby, flows between streams 39 and 40 toward and into theconnecting zone. It fills the space in leg segment not filled by streams39 and 40, and prevents the entry of residual gases from chamber 17 intothis portion of the zone. It also assists stream 40 in supplyingdiffused air to the connecting zone and, to some extent, in charging theignition chamber.

The third method of supplying excess air to the ignition chamberutilizes an auxiliary air supply, as shown in Figure 8. In this designan auxiliary annular groove 93. which forms an air receiving space, isprovided adjacent the spark plug and air is stored therein during thecompression cycle. The air is supplied through passage 94 which joinsgroove 93 tangentially at a point 95 and joins the connecting zone 19 atthe point 96 where stream 42 impinges normally on side wall 43. Duringthe compression cycle a portion of stream 42 flows through passage 94ina stream 97 which enters annular groove 93 and circulates therein asshown. .At the same time the fuelair mixture normally supplied to theignition chamber circulates in a stream 60 in the same direction ofrotation as stream 97, and because of the parallel flow the fuel mixturedoes not appreciably intermix with the air in groove 93 during thecharging cycle. After the mixture is ignited by plug 25 this additionalexcess air is present to mix with the burning gases and join in thecombustion.

It is possible to vary the fuel-air ratio in the ignition chamber quitewidely during the operation when it is pro vided with a localized fuelmixture and excess air by the methods described because the greatcleaning action exerted on the spark plug and ignition chamber walls bythe excess air immediately cleans up any deposits which may momentarilybe formed by an over-rich mixture.

The fuel charge preparation means are located in the connecting zone,and are designed to produce the fuel charge for the ignition chamber.The quantity of fuel supplied to said means is always substantiallyfixed for all engine speeds and loads, but a manual adjustment is alsoprovided in order that the fuel-air ratio of the charge may be changedsomewhat to obtain the optimum performance.

The adjustment is made by rotating the injector 27 axially in its socketand locking in any desired position by means of lock nut 28. The nozzleorifice 31 is'drilled substantially perpendicular to the axis ofrotation of the injector, and consequently the point of impingement 34of fuel stream 32 can be readily moved nearer to or further away fromthe ignition chamber 18 by rotating the injector. Since the ignitionchamber charging stream 40 cuts along a fixed line 73 directly acrossthe elongated fuel body formed by fuel stream 32 after impingement, thequantity of fuel on the ignition chamber side of said line of divisionis varied simply by changing the point of fuel impingement relative tosaid line. Rotating the injector clockwise when viewed from the outsideof the engine as 8 in Figure 1 increases the quantity of fuel in theignition chamber charge, and vice versa.

The liquid fuel that is deposited by the injector for pro ducing theignition chamber charge is vaporized in two differentways, and forms twodistinct types of vapors. The first type is produced by a simple, coolvaporization, induced by passing the circulating stream 56 repeatedlyover the liquid fuel body during the compression cycle, while the secondtype of fuel vapor is produced by a flame induced vaporization processwhich acts on fuel that has been carried over from the previous cycle.

The second type of vapor is produced in the following manner. The liquidfuel charge that has been initially deposited on the fuel receivingsurface 33 during the intake cycle by injector 27, is moved, during thecompression cycle, by charging stream 52 into a new location in thevapor collection zone 89, as shown by outline 88. During thisdisplacement some of the fuel is vaporized into the first type of vaporby streams 52 and 56 and is delivered to the ignition chamber while theremainder is retained in the liquid state in zone 89.

After ignition the ignition flame passes in a stream 76 over theretained fuel and heats the fuel, and a portion thereof is burned bymeans of excess air contained in the flame. The flame from the fuelcharge in the combustion chamber also passes, in a stream 77, at leastpartially over the remaining fuel to further heat and burn the fuel. Theburning by both flames removes excess fuel from thc fuel receivingsurface and maintains the surface in a stable condition at all times byburning off any carbon that becomes more than a few mils thick. Theflame cannot, however, completely remove all carbon from the cooledsurface, and a thin layer of soft carbon remains in which a smallquantity of fuel is retained. The retained fuel is not completely burnedby the passing flame because of the low temperature at which it is heldby the engine cooling system, but it is nevertheless partially oxidizedthereby and is carried over to the following cycle for subsequentvaporization.

In order not to cover and quench the partially oxidized fuel, the fuelcharge for the following cycle is injected and deposited, as shown byoutline 35, in a zone separate from outline 88, and the fuel vapors fromthe retained fuel within outline 88 rise and col set in vapor collectionzone 89 during the intake and compression cycle. The vapors from theretained fuel are held in the collection zone by the diffused airforming the first and second pressure zone barriers and are displacedinto the ignition chamber by stream 57 during the time the newlyinjected fuel is being displaced from its initial position 35 to itsfinal position 88.

It is a feature of the fuel preparation means that, in preparing the twotypes of vapor, the accidental formation of atomized fuel is effectivelyminimized. During vaporization of the fuel, the circulating stream 56centrifuges any fuel droplets formed onto the side Walls of thecollection zone 89 for revaporization, and a similar centrifuging actionis also obtained in the annular passage 58 in the ignition chamber.

An additional feature is that delayed vaporization of fuel from thevaporizing surface in the engine is eliminated. During the power cyclethe vaporization of fuel from the fuel receiving surface is momentarilyterminated by burning off all the exposed fuel on the surface with theexcess air in the combustion flame, and this makes the vaporizationprocess intermittent. This is an essential function in a combustionsystem that is to operate with a clean and odorless exhaust.

The type of vapor that is obtained from fuel which has been burned overWhile held on a cool surface is much more ignitable than the first typeof vapor produced, and when properly concentrated, makes any fuelspark-ignitable and even makes low cetene number fuels self-ignitable atlow compression ratios. Fuel which is normally self'ignitable only athigh diesel pressures is, when prepared according to the processdescribed, not onlv spark ignitable but is self-ignitable in the sparkignition range of compression ratios such as 10.11 to :1 or even lower.Operation with self-ignition is equivalent to that with sparkignitionexcept that no spark is required. The spark plug insulator actsto initiate ignition and, because ,of the excess air which is provided,remains perfectly clean at all times.

There is no detonation or knocking of any kind in the ignition chamber,either with spark ignition or selfignition. This isinsured by having thefuel charge composed entirely of .cool fuel vapors and by burning it ina small, .cool and clean chamber entirely free of deposits. It is animportant feature that the fuel charge contains ,no liquid atomizedfuel, because atomized fuel can cause fouling of the spark plug anddetonation and also the formation :of deposits which lead topre-ignition. The formation .of heated fuel vapors in the fuel charge isalso avoided, because high temperatures decompose the fuel into productswhich .are diffi'cult to ignite and are slow burning.

The cool fuel vapors of the .second type are produced #by a vaporizationprocess which depends almost entirely on heat from an intermittent flameapplied to the surface of the fuel, and not from residual heat in thefuel receiving surface. Consequently the production of this type ofvapor is almost entirely independent of engine temperature, and theengine is designed to operate to a very large extent on this type duringthe warm-up period. As the cooling water on the opposite side of thewall that forms the fuel receiving surface reaches the usual operatingtemperature range of 160 to 180 degrees Fahrenheit and the fuelreceiving surface reaches its normal temperature, a larger proportion ofthe fuel charge .is vaporized during the compression cycle to form thefirst type of cool vapor, and proportionately less of the fuel iscarried over for the production :of the second type of vapor. The resultis that the :engine operates uniformly at all temperatures on acombination of both types of vapor, and does so even with'fuels havingwidely different volatility.

It is a feature of the fuel charge preparation means that the fuelreceiving surface exerts a positive control on the temperature of theliquid fuel deposited thereon. It acts initially as a heat source toheat the newly injected fuel to promote preflame reactions andvaporization by vaporizing stream 56, and it also acts as a heat sink tocool the retained fuel during the period when it is subjected to theheat of the ignition and combustion chamber flames. This dual actioninsures the production of uniformly cool fuel vapors of both typesregardless of engine speed or load.

The function of the fuel receiving surface 33 in chamber 17 is somewhatsimilar to that of the fuel receiving surface in the fuel preparationmeans. During the compression cycle it heats the liquid fuel depositedthereon and holds it in an exposed position where it can be acted on byair to promote pro-flame reactions. The temperature of the surface 33 ismaintained 'by the cooling water at a substantially uniform level at allengine speeds and loads, and, as in. the-fuel charge preparation means,it heats the fuel to a uniform temperature near to but below the boilingor thermal distillation temperature of at least the major portion of thefuel. Since most fuels contain fractions having substantially differentboiling points, the more volatile ends are frequently vaporized, but themajor portion of the fuel is always held in the liquid state on the fuelreceiving surface.

During the combustion cycle when the gas temperatures above the fuel arevery high, the fuel receiving surface also maintains the liquid fuel ata uniform temperature, but functions as -a heat sink or cooling meansinstead of as a heat source. Because of this, the temperature of everyincremental portion 'of liquid "fuel, up to .the instant of itsvaporization and combustion, is maintained substantially the samethroughout the cycle. Thus, the last 10 fuel to burn passes through thesame temperature cycle as the first fuel to burn, and a positivecontrolof the .combustion is attained.

In order to minimize pre-vaporization of the fuel on surface 33 duringthe compression cycle, the air velocity over the fuel is kept at .a lowlevel by means of the described system of converging .air flows. Inaddition to this, a localized circulation is established above the fuelbody which collects any fuel vapors that are accidentally formed andholds them in .a position directly above the liquid fuel to furtherminimize vaporization.

The localized circulation is obtained by directing stream 41, by meansof the notch or channel 98 in leg segment 20, to flow centrally into thecombustion chamber 17 at a level somewhat above the retained liquid fueland to intercept the centrally rising air stream 75, which unavoidablycarries some fuel vapors away from the fuel body. The flow 75 is turnedback toward the bottom of chamber 17 as shown by line 99in Fig. 5, andthe fuel is all concentrated on and near the center 69 of said wall 70.The axial flow line about which the fuel vapors circulate is essentiallya single ended axis of rotation located above the fuel body, and itintercepts a wall at only one end.

The fuel is not only localized during the compression cycle, but alsoduring the combustion cycle. In order to minimize fuel dispersion duringcombustion, the fuel receiving surface is made concave in form in thebottom of the combustion chamber and the fuel is deposited thereon. Whenthe ignition flame .flows against the fuel it displaces the fuel alongthe concave surface and tends to hold the fuel against the surface untilit is vaporized. This action prevents dispersion of the liquid fuel intothe air in the form of atomized droplets, and prevents delayedafter-burning and gum formation. The fuel-air mixture, as it is formedand burned, never contains either atomized fuel or .prevaporized andoverheated fuel vapors.

It is an important feature of the engine design that the ignition andcombustion chamber zones most remote from the engine cylinder arecharged with excess air. In the ignition chamber the excess air joinswith the ignition flame, and, aside from its other functions, acts onthe liquid fuel on fuel receiving surface 33 to promote its combustion.This heated air, directly in the vaporizing flame, causesa combustion atthe fuel surface the instant the liquid fuel is vaporized. The delaybetween vaporization and combustion of the vaporized fuel is reduced toa minimum, and this is most efiective in preventing detonation.

Similarly, when the flaming gases in the combustion chamber flow in astream '77 toward the cylinder 10, the excess air which was localized inthe upper zone 67 during the compression stroke becomes mixed with theflaming gases and acts to burn the fuel remaining on the fuel receivingsurface. In both cases the fuel is held on the surface while the heatedair is swept over it. This produces a localized burning at the fuelsurface which is always complete regardless of the quantity of excessair present. The fuel does not become dispersed prior to combustionbecause it is held in a concentrated body until the conditions forcombustion are correct. Because of this action it .is possible to burnsmall charges properly in the presence of excess air even at lowcompression ratios, and a satisfactory part load operation can beattained.

The fuel body is held in a position between the most remote end of thecombustion chamber and the engine cylinder, at a point where air sweepsover it in flo ing toward the cylinder on the power cycle. Consequentlyno fuel vaporization can take place in insuflicient air, because thelast gases leaving the combustion chamber during the power cycle arecapable of supporting combustion and clean out the entire combustionsystem on each cycle. This not only maintains the system in a stablecondition, but gives a clean and odorless exhaust 11 from which thecharacteristic fuelodor of conventional fuel oil burning engines isentirely absent.

The combustion is of the constant volume type at light loads, and acombination of constant volume and constant pressure at full loads. Theignition flame induces the constant volume combustion, while the secondsweep of flame from the combustion chamber to the cylinder induces theconstant pressure combustion. This is the optimum type of burning formaximum efiici ency and smoothness of operation, especially whenoperating in the desirable ratios of compression around to l.

When it is cold, the engine is started with volatile fuel such asgasoline. A carburetor, or equivalent means (not shown), is employed tosupply the fuel, since the engine will operate as a conventionalgasoline engine with throttled air control when the normal injected fuelsupply is cut off. It is usually necessary only to bring the engine upto its normal operating speed on the starting system, after which thecarburetted charge is cut off and direct fuel injection with full air isbegun. if volatile fuel, or a wide cut type including volatilefractions, is being injected, or in any event if the engine is warm,starting is accomplished by simply injecting fuel in the normal mannerwhile cranking.

Figures 9 and 10 show a modified embodiment of the engine also capableof carrying out the combustion process of the invention. This designdiffers from the preferred form in the connecting zone means used forcharging the ignition chamber and combustion chamber during thecompression stroke and in the design of the vaporization means, ignitionchamber, air cell, and the general arrangement of parts.

This engine is also shown as a four-cycle, water-cooled, valve-in-headtype. A cylinder with reciprocating piston 101 therein has its upper endclosed with a cylinder head 102, and water jackets 103 enclose saidcylinder and cylinder head. Intake valve 104, working in intake port 105and exhaust valve 106 working in exhaust port 107 are operated in theconventional manner by mechanism not shown. Formed in the head 102 andenclosed by the jacket 103 is a substantially cylindrical combus tionchamber 103. it is joined tangentially at a point adjacent its bottomwall 111 by a passage 109 lying in a plane normal to the axis 110 ofsaid chamber. The other end of said passage joins the clearance space112 above the piston 101.

A spiral ramp 113 whose helix is concentric with axis 110 is formed onthe side wall 114 of chamber 108 and surrounds the central bottom wall111. The ramp begins on the bottom wall 111 at a point near passage 109and spirals upward in a half turn to blend into overhanging wall 115.Said overhanging wall lies in a plane substantially parallel to thebottom wall 111 and extends into chamber 108 to overhang that portion ofsaid bottom wall directly adjoining passage 109. This forms acommunicating zone lying between the combustion chamber and the passage109.

An ignition chamber 116, located adjacent the combustion chamber 108,has a spark plug 117 at its upper end. A globular bowl or intermediatechamber 118, placed between ignition chamber 116 and chamber 108, isjoined tangentially, near its top, by a passage 119 which opens directlyinto cylinder 100. This passage is tapered, to diffuse air flowing fromsaid cylinder to the bowl 118. An annulus 120, formed around the lowerside walls of the ignition chamber, is joined tangentially by passage121. The other end of passage 121 joins the bowl 113 tangentially nearits bottom in a plane passing vertically through the center of the bowl.A s=cond passage 122 also joins said bowl tangentially near its bottombut in a plane normal to the plane of passage 121. Said passage 122 isparallel to passage 109 and joins chamber 108 adjacent the centralbottom wall 111 and below the level of ramp 113.

Globular bowl 118 and its associated, passages 119, 121 and 122 comprisea structure which functions like the connecting zone of the preferredform. Its distinguishing feature is that it is charged with air througha passage separate from the combustion chamber charging passage, insteadof by air from a flow dividing means in a single passage as described inthe preferred embodiment.

An air cell or air receiving chamber 123, located ad- 'acent theignition chamber 116, is joined thereto by a small passage 124 whoselength axis is substantially norrnal to the side of the ignitionchamber. A second passage 125 is joined to the diffuser passage 119 andopens tangentially into the side wall of the ignition chamber 116,forming a short groove or open channel 126 therein. The groove joins thepassage 124 substantially normally in a plane parallel to the plane ofthe annulus 120.

An injector 127 has a nozzle 128 which projects into the globular bowl118. The nozzle has a single large orifice through which a fuel pump(not shown) injects fuel into said bowl in an unatomized stream 129. Thefuel impinges obliquely on the bottom wall of said bowl at a point 130and spreads out into an elongated body extending from point 130 intochamber 108. The full load fuel outline is indicated generally byoutline 131 and the small idle charge by outline 132 in the bowl 118.

The engine operates on the same basic cycle as the preferred embodiment.Fuel is injected into the engine preferably just after the beginning ofthe intake stroke, althoughinjection may extend somewhat into thecompression stroke. During the compression cycle, air is displaced intothe combustion chamber 108 in a stream 133 which flows up the ramp 113,over passage 122, and above overhanging wall 115. It continues to flowin a circular path around and out of contact with the fuel body onbottom wall 111, which minimizes prevaporization. At the same time, airis displaced into the bowl 118 in a stream 134 which is diffused inpassage 119 before it enters the top of the bowl tangentially. Thestream flows spirally downward into the bowl and divides into stream135, which sweeps over the fuel body 132 in the bowl and passes into theignition chamber, and into stream 136 which passes into the combustionchamber.

Stream 134 is diffused in order to form a barrier in passage 122 withthe branch stream 136. This resists the entry of residual gases into thebowl 118 and the ignition chamber 116 from chamber 103. The diffused airalso provides a low resistance path for the ignition flame afterignition. Passage 122 opens into chamber 1% below the ramp 113 near thecenter of said chamber where the force tending to drive the rotatinggases into bowl 118 from chamber 108 is a minimum. Side wall 142 iscurved to make passage 122 divergent to further minimize theinterception of rotating gases.

The air cell charging stream 137 flows through passage 125 and along thegroove 126 and is crowded into air cell 123 by ignition chamber chargingstream 135. The two streams flow in the same direction and do notreadily intermix, so that air enters the air cell while the fuel-airmixture of stream fills the ignition chamber.

After ignition of the fuel-air mixture in the ignition chamber by sparkplug 117, the flaming gases pass in a line 138 through the bowl and intothe combustion chamber to initiate combustion therein. The flame inducedreaction proceeds in a progressive manner as in the preferredembodiment. The burning gases in chamber 108 flow in a line 139 into theclearance space 112 and are deflected by overhanging wall 115 to flowforcefully over any fuel remaining in fuel body 131. This induces afinal combustion which completes the reaction.

In passing through the bowl, the ignition flame sweeps forcefully overthe bottom wall and any fuel remaining thereon after the compressioncycle is spread laterally up the side walls of the bowl as shown byoutline 141. Air in the bowl itself plus air from air cell 123 enablesthe flame containing excess air.

13 ignition flame to burn a substantial portion of .the retained fuel,but, as -in the preferred for-m,1some.fuel.remains on the cooled surfaceafter the passage of the flame and is vaporized on the subsequent cycle.This provides readily ignitable fuel vapors for the ignition chamber.

When the engine is cold and a considerable quantity of fuel remainsunvaporized .at the end of the compression cycle, the ignition flameheats and spreads the fuel widely over the side walls of the bowl, sothat the vaporizing stream 135 readily vaporizes the fuel on .thesubsequent cycle. This makes the vaporizing action substantiallyindependent of engine temperature.

Air from the air cell 123 flows into the ignition chamber in a stream140 during the time when pressure is falling in the ignition chamberafter peak combustion pressures have been reached. Passage 124 isdisplaced from the opening of passage 125 by the length of groove 126 inorder to minimize loss of air down said passage 125 during the dischargeperiod. The excess air added to the final combustion in the ignitionchamber produces a lean flame therein which maintains the spark plug andignitionchamber in aclean condition.

Air fills the top of the bowl at the time of ignition and when theignition flame passes through in a looped 'flow as shown, this air ispartially displaced with the flame into the combustion chamber toproduce thereby an ignition The remaining air supports combustion in thebowl, and with excess air from air cell 123, maintains the bowl andconnecting passages in a clean condition at all :times.

Figures 11 and 12 show another embodiment of the invention. This enginehas separate fuel injectors for supplying the fixedignition charge andthe variable power charge, and it has a special type of ignition chamberwhich operates .on self-ignition at low pressures with means differentfrom those shown in the preferred embodiment.

The engine is :a conventional four cycle, water cooled, valve-in-headtype in which-the intake and exhaust valves are operated in the ;usualmanner. The cylinder :150 is provided with a clearance space 151 abovethe piston 152, and the combustion chamber 153', located adjacent thecylinder, is :joined thereto by passage '154. An overhanging wall orbaflie 156, parallel to bottom wall 155, projects from the side wall ofchamber 153 :at a level ust .above .the opening of passage 154, andoverhangs a portion of the bottom wall 155 at the point where pas- .sage15.4 opens .tangentially into the combustion chamber. An ignitionchamber 157, located adjacent the combustron chamber at a level above.the passage 154, is joined thereto by an inclined passage 158. Theupper-end of said passage blends into the spiral bottom end wall 159 ofthe ignition chamber, and the lower end opens into the combustionchamber just under the vbafde 156. The passage is oriented so that anaxial projection will lie on the center of the bottom wall 155.

The ignition chamber has a :spark plug 160 screwed on top and an aircell 161 joined to one side by a short inclined passage 162. A fuelinjector 163 projects into said ignition chamber and a second injector164 projects into the combustion chamber 153. The entire cylinder 150,combustion chamber 153, and connecting passage 154 are enclosed by waterjacket 165. One-half of the ignition chamber 157 and one-half of theinclined passage 153 are enclosed by the water jacket, while theremainder of the passage and ignition chamber are cooled only byradiation. The uncooled half of the ignition chamber includes the air.cell 161.

The cycle of operation is basically equivalent to that of the preferredembodiment, but differs in detail. Prior to the compression stroke afuel pump (not shown) and injector 163 deliver liquid fuel in a stream166 onto the upper water cooled end 185 of the spiral end wall 159. Thefuel flows both by the force of injection and of gravity toward thelower uncooled end 186 of said wall as shown by the outline 167. Thefixed quantity of fuel injected is .suflicient to form .a nearstoichiometric fuel-air mixture in the ignition chamber when the fuel isvaporized. At orabout the same time the second injector 164 and a fuelpump (not shown) direct an unatomized stream of fuel 168 onto the centerof bottom wall and form a fuel body whose outline is indicated generallyby the line 169. This fuel charge is variable in quantity and controlsthe powerof the engine.

During the compression stroke, air from cylinder 150 flows up thepassage 154 in a .line 170 and circulates horizontally around chamber1'53. .A portion .of theair flows :under the ba'flle 156 in a branchstream 171, while the remainder flows above in a stream 172. Stream 171circulates around the fuel body 169 and the fuel remains substantiallyin the liquid state during the compression stroke. The cross section ofthe lower open end of passage 1 58 is preferably made, as shown, with asharp leading .edge 173 and some of stream 170 is diverted thereby intobranch stream 174 which enters ignition chamber 157 at a low velocity.

The fuel in the ignition chamber is vaporized principally by residualheat in the uncooled portion of the spiral end wall and not by a highvelocity air stream as in the preferredembodiment. The fuel injectedthrough injector 163 flows from the upper cooled end 185 toward thelower uncooled end 186 of the spiral end wall 159, and flows over asurface which becomes increasingly hotter. As the fuel flows down thistemperature gradient vaporizer, it becomes increasingly hotter and apoint is soon reached where self ignition temperatures are attained. Asengine loads and temperatures vary, the self-ignition point moves up anddown along the surface, providing a de- .pendable ignition source overwidely varying operating conditions. i

When ignition occurs, the ignition flame .flows in a stream 177 down thepassage 158 and on through the recessed outer portion 17:6 thereof intothe combustion chamber. In entering said chamber it flows above the highvelocity stream 170 so that it is not dispersed thereby, and impinges onthe .fuel body 169 in the zone of :localized circulation in the centerof bottom wall 155.

Combustion takes place in the manner already described. After theinitial flame induced combustion, gases leaving the chamber 153 aredeflected downwardly by baflle 156 to flow forcefully over the fuel onthe bottom wall, and the remaining fuel is vaporized and burned.

During the compression cycle air stream branches off of charging stream174, before said stream reaches the fuel body in the ignition chamber,and charges air cell 161 with air. When the combustion pressure beginsto fall, this air flows upwardly from the air cell 161 through .passage162 and enters the ignition chamber in aline 179. The air mixes with thefinal flame to produce a combustion with diminishing fuel-air ratio andmaintains the chamber relatively clean and free of carbon.

To bring the engine to an operating temperature it is preferably startedand warmed up slightly by operating momentarily on the Otto cycle withgasoline carburetor and spark ignition. The spark plug 160 is providedfor obtaining the initial ignition, but it is not required thereafter.Other conventional methods of starting low compression, self-ignitionengines may however also be employed if desired, such as heating thevaporizer by external means before starting, or equivalent methods.

Another type of engine is shown in Figures 14 and 15 which alsoillustrates the broad scope of the invention. This is an engine in whicha separate combustion chamber is designed like the ignition chamber ofthe preferred embodiment, and operates on a combustion cycle which isessentially equivalent to that employed in said ignition chamber. Inorder to maintain a uniform fuel-air ratio in the chamber over the loadrange, the air is throttled .at part load as in a conventional gasolineengine, but as will be described, some excess is also provided.

The engine as shown is a conventional four cycle, water cooled type. Acylinder 224) has a piston 221 therein,

embodiment.

and a cylinder head 222 closes the upper end of said cylinder to form acombustion space 223 between said head and piston. This combustion spacewill be defined as the combustion chamber. Formed within said head is acavity 224 which is separate from the engine cylinder, and this will bedefined as the ignition chamber. An annular groove 225 is provided atthe lower end of the ignition chamber and a passage 226 joins thisgroove tangentially and connects said ignition chamber with combustionchamber 223 in cylinder 220. The bottom wall 227 of the ignition chamberis formed as a spiral ramp, and the lowest point thereof blends into thelower wall of passage 226 at the point 228 and the highest point liesjust above the upper wall of said passage 226 at the point 229. A fuelinjector 230 projects into said annular groove at a point 231 justbeyondwhere passage 226 joins said groove.

A second annular groove 232 surrounds the ignition chamber at its upperend and a spark plug 233 is screwed into said chamber at a pointsubstantially concentric with said groove. An auxiliary air passage 234opens into the passage 226 at a point 235 where passage 226 turns tojoin annular groove 225. The other end of passage 234 joins upperannular groove 232 tangentially at a point 236, and the passage isoriented so as to cause air entering groove 232 from passage 234 to flowin the same direction of rotation in said annulus as air entering thelower annulus 225 from cylinder 220 via passage 226.

The engine operates in the following manner. A quantity of liquid fuelis injected into the periphery of the annular groove 225 by means ofinjector 230 preferably during the intake stroke, but the fuel may beput in later, during the compression stroke, if desired. It is injectedin a liquid stream 240 and is deposited in a body 241 on thewall ofgroove 225 as shown. During theintake stroke, air throttle 237 in intakepassage 23S limits the air drawn into the cylinder past intake valve 239to an amount insuflicient to produce a near stoichiometric fuelairproportion with the injected fuel.

During the compression cycle the air in cylinder 220 is displaced in astream 242 through passage 226 and enters annular groove 225 tocirculate therein and sweep over the fuel body 241. The circulating airin groove 225 sweeps the liquid fuel along in the periphery of thegroove, and the spiral ramp 227 directs the fuel stream over and aboveentering air stream 242 so that the liquid fuel is not aspirated intothe entering air stream to form an atomized fuel charge, but remainsfirmly in contact with the wall of the annular groove until it isvaporized. The air and fuel vapor mixture formed in the groove 225 flowsspirally upward along the side walls 244 of chamher 224 in a pathgenerally indicated by flow line 245. This flow continues in aconverging spiral 246 toward and past the spark plug points 247, thenturns downwardly in an axial flow 248.

During the compression cycle some of the air in stream 242branches offin a stream 243 and flows through auxiliary passage 234 and into upperannular groove 232, where is circulates, as shown, in the same directionof flow as the circulating fuel and air mixture 245. This minimizesintermixture of the air and the fuel mixture, and the groove 232 becomessubstantially filled with air at the time ignition occurs.

The combustion process is substantially equivalent to that described inthe ignition chamber of the preferred The central core of fuel and airmixture, which is in substantially stoichiometric proportion, is ignitedby spark plug 233 and burns, while surrounded by the excess air ingroove 232. The combustion heats the excess air, and during theturbulent outflow 249 of the burning gases into combustion chamber 223,the air mixes with said gases to produce a lean, clean burningcombustion.

If very volatile fuel is injected it may completely vaporize during thecompression cycle, in which case the 16 last air to enter annulus 225and chamber 224 will contain very little fuel and will surround thecentral fuel charge with excess air. In this event, the upper annulargroove 232 and itsair supplyare not necessary. The groove is, however, amore certain source of excess air and makes operation possible withwider cut fuels. If any-fuel remains unvaporized at the end of thecompression stroke, the excess air in stream 249 sweeps over it duringthe power cycle and burns it directly in groove 225, or the fuel may becarried into the combustion chamber 223 for combustion in the airtherein. This final burning takes place in a manner substantiallyequivalent to the burning of liquid fuel in the combustion chamber ofthe preferred form of engine.

The combustion systems described, with the exception of the last onewhich operates on the Otto cycle, are designed to operate on a widevariety of fuels, from volatile gasolines, through the intermediatedistillates and wide cut JP types, to heavy diesel fuels. An engineemploying these systems is capable of operation over the entirecompression range, and at any compression selected, operates on a fullexcess air cycle at all loads and obtains the excellent part loadefliciency characteristic of this type of engine. The clean, gum-free,odorless and knock-free combustion is obtained at all compressionratios.

Adequate pre-combustion preparation plus progressive charge formationand ignition, and positive fuel temperature control during combustion,are three factors which contribute decisively in producing a combustionwhich is distinctly different from conventional practice. The criticallife cycle of every particle of fuel during its burning period issubstantially the same, whether it is the first or last fuel to burn.Nowhere in the entire cycle is a condition obtained in which the fuel isprepared for detonation in a manner equivalent to that of the fuel inthe end gas charge in a gasoline engine, or the fuel in the chargeformed in a diesel engine during the ignition delay period. Nor is thereany atomized liquid fuel in the combustion flame, particularly duringthe late stages of combustion, to detonate or become distilled andpolymerized into gum and carbonaceous deposits and formed into evilsmelling by-products. It is significant that the combustion obtained bythe described process is not only clean during normal operation, butalso during periods of deceleration, acceleration and prolonged idling.The unthrottled air charge, no fuel additives, and uniform combustion inthe ignition chamber under favorable conditions at all engine loadsmakes possible an odorless exhaust which is always free of smoke fromoil, fuel or fuel-additives. Those engine exhaust by-products which inconventional engines contribute so much to air pollution are entirelyabsent.

The present application is a continuation-in-part and is connected bycopendency with our prior but now abandoned patent applications asfollows:

Serial No. 115,544, filed December 12, 1936, entitled Method ofEffecting Non-detonating Combustion in an Internal Combustion Engine andMeans for same;

Serial No. 305,390, filed November 20, 1939, entitled InternalCombustion Engine and Combustion Method;

Serial No. 448,042, filed June 22, 1942, entitled Com bustion Chamber;

Serial No. 448,043, filed June 22, 1942, entitled Internal CombustionEngine;

Serial No. 448,044, filed June 22, 1942, entitled Ignition Means;

Serial No. 517,452, filed January 7, 1944, entitled Combustion Chamber;

Serial No. 549,026, filed August 11, 1944, entitled Combustion Chamber;

Serial No. 715,672, filed December 12, 1946, entitled Oil CombustionProcess and Engine;

Serial No. 93,376, filed May 14, 1949, entitled Excess Air CycleInternal Combustion Engine and Combustion Process;

Serial No. 29,0,l? :1,v filed-May 2-7, 1952, entitled; Excess Air Cycle-Internal Combustion Process; and

Serial No. 290; 132;. filed May 27, 1952;, entitledExcess Air CycleInternal Combustion Engine.

Reference is also directed to our companion application, filed January16; 1956; Serial- No 559152; entitled Combustion Engine Process, allowedJanuary 16,. 1 957.

It is understood-that the invention is. not limited to the precise.structure shownand' described, but also includes such modificationsasmay be embraced within the scope of the appended claims.

We claim:

1. In an internal combustion engine of the type having a pistonandcylinder, the combination of: a combustion chamber separate-from theengine cylinder; a passage connecting the cylinder to the combustionchamber, said passage arranged: to direct air entering the combustionchamber from said cylinder to. circulate about an axis of rotationintercepting a wall of saidicombustion cham-- her at least atone point;an ignition chamber; a pas-sage connecting the ignitionchamber to thecombustion chamber, said passage arranged to direct gases entering thecombustion chamber from said ignition chamber to=fiow over and againstsaid wall at leastinclose proximity to said point of interception ofsaid axis of rotation with sad:wall; and means for'supplying liquid fuelto said wall surface in a. region in close-proximity to said pointofinterception of saidwallsurface by said axis.

2. Inan internal combustionengine of'the type having a cylinderandzpiston, the combination of: a combustion chamber separate from saidcylinder; a communicating zonee'joining said combustion chamber; apassage joining; said cylinder and said communicating zone, and arrangedto direct air flowing from said cylinder into said combustion chamberviasaid zonein a stream which passes through only a portion of saidzone; and r'n'eansfor deliyeringlit uid fuelto at least a portion ofthat part of said zonejn'otswept: by said air stream entering saidcombustion chamber via said zone but swept by gases flowing fr om"saidcombustion chamber to said cylinder via said zone.

' 3. In an internal combustion engine having a piston andzcylinder, thecombination of: 'acombustion chamber separate from: said cylinder, saidchamber being substantiallyafigure ofirevolution with abaffle projectingfrom: a. side wall there'of' in a plane'subst'antially normal to theaids-'of revolution and spaced from an end wall of: said chamber; apassage joining said cylinder; and joining saidcombusti'on' chamber at apoint between said battle and said end wall; and: an ignition chamber incommunication with said combu'sti'on'charnber.

4'. In an internalfcombustion engine of the type having a cylinder. andpiston, the combination. of:. a combustion chamber separate from theengine cylinder; an ignition chamberyand a;T'-shaped-passage havingalegand' two arms which .formaconnecting zone, of which-the leg joinsthe enginecylinder, one arm'joins the combustion chamber,.and theotherarm-joins theignition chamber.

5'. 'Inianinternal combustion engine of thetypehaving a cylinder andpiston,- the combination of: a combustion chamberrseparatefromtsaidcylinder; an ignition-chamber; a first passageijoining saidcylinder and communicating with said combustion chamber; asecond passagejoin ing the ignition chamber; .and'a'T-shaped connecting zone iDiWhlCh'thefirst 'passageljoins, at least'in'part, the leg of the T-,thesecond-passage joinsone arrmof said Tand the other armof the Tcommunicates with said'combus: tion chamber.

6..In an internal: combustion engine of the typehavinglacylinderandpiston, the combination of: a combustion chamber. separate from theengine cylinder;.an ignition chamber; at smallv passage joining saidignition chamber; and a T-shaped passage'having a leg'a'nd two arms;whichform a connectingzone, of Whichthe'leg joins the engine cylinder,one arm joins the combustion I8 chamber and the other'arnr joins saidsmall passage which latter hasa cross-section less than that'ofsaidotherarm.

7. In an internal combustion enginehaving a piston and cylinder, thecombination of: a combustion chamber separate from the engine cylinder;an ignition chamber; a T-shaped passage having a leg segment and crossarm which forms a connecting zone, of which the leg segmentjoinsthe-engi'ne cylinder, and the combustiomchamber andignitionrcha'mber joinoppos'ite ends of said cross arm; and araise'd'rib segment on the side of said cross armopposite the legsegment.

8. In an internal combustion engine of the typehaving ya-cylinder andpiston; the combinationof: a combustion chamber separate from the enginecylinder; an ignition chamber; a passage joining the ignition chamberand communicating with said combustion chamber; passage means configuredand arranged to divide thea'ir flowing from the cylinder toward thecombustion chamber into a: first stream-flowingsubstantially wholly intosaid combustion chamber and asecond stream separate of said firststream; andmeans for directing at least a portion of said second'stream'into said ignition chamber passage, andanyremainde'r of saidsecondstrearn: intosaid conibustion chamber. i p

9. In an internal combustion engine of thetype having acylinder' andpiston, the"combination'of*:- a combustion'chamber separate from-theengine cylinder; an ignition chamber; a passage joining theignitionchamber and communicatingwithsaidxconibustion chamber; air flowdividingmeans' havingat least two air conveying elements incommunication with said combustion chamber; aqaaSSage fmm 'saidcylinderto sa'id flow d-i ding-means arranged to direct air flowing: from'saideyIinde'r' more forcefully into aafirstelement' ofsaid'flow'dividing means thaninto' a second element; means fordirectingthe air flowing; in said second. element substantially whollyiiito said combustiontchamberg and means-for directiiigat least aportion of the air flowing in sa idfi'rs t elenientintosaid ignitionzchamber passage and any remainder thereof into said combustion chamber.

.10. Ima-n'internal combustion engine'- f thejtype having;apiston andcylinder;tlie"combinat on of; a combustion chamber separate. from the"engine c'ylinder; an ignition chamber; a passage joining saidf ignitionchamber and'-communicating'with' said combustion chamber; passage means;including a'irflow dividing means navia atleast'twozair'conveying'el'eme'nts, arranged to direct air fromthercylinder'into the combustion chamber in a'first stream flowing intosaid combustion chambervia one conveyingt'element anda second streamfi'owingvia another conveyingielement at least'in part'intosaid'ignition chamber; and" aspiration means combinedwith saidpassage'means and responsive to air flow therethro'ugh fordra'wingairrf-fom said'oth'er conveying element to diifus'e said airstream therein. V

11. In an internalcombu'stion engine'having a cylinder and pistomthe.combination of: a com'bus'tion chamber separate from 'the engine:cylinder; ignition chamber in -communication: with said combustionchamber; p'a's- ;sa ge :means from 'said cylinder tosaid'combus'tionchaniher and saidignition' chamber, said passage meanshavin flowk dividing means to divideair flowing therethrough fromsaidbylindeninto an ignition chamber charging stream anda combustionchamber chargingstream; air

aspiration means in combination with 'said passageto difstantiallyconcentric therethrough; wall means defining a second passage joiningsaid cylinder, said passage having a length axis passing substantiallyconcenrtic therethrough, and joining said first passage with the lengthaxes of said first and second passages lying in planes displaced fromeach other at the juncture of said passages by at least half the nominaldiameter of said first passage and with the angle between said axes whenprojected one upon the other less than 180", said configuration forminga junction between said passages in which said second passage issubstantially tangential to said first passage, the walls of saidpassages joining in a sharp edge where the wall of said second passagenearest the axis of said first passage first intersects said secondpassage; and an ignition chamber in communication with said combustionchamber.

13. In an internal combustion engine of the type having a cylinder andpiston, the combination of: a combustion chamber separate from theengine cylinder; wall means defining a first passage joining saidcombustion chamber, said passage having a length axis passingsubstantially concentric therethrough; wall means defining a secondpassage joining said cylinder, said passage having a length axis passingsubstantially concentric therethrough; and joining said first passagewith the length axes of said first and second passages lying in planesdisplaced from each other at the juncture of said passages by at leasthalf the nominal diameter of said first passage and with the anglebetween said axes when projected one upon the other less than 180, saidconfiguration forming a junction between said passages in which saidsecond passage is substantially tangential to said first passage; curvedwall means forming an extension of the walls of said first passage atthe point of juncture with said second passage, said curved wallsforming substantially an involute groove or channel passing at leastpartially around said first passage in open communication therewith onits open inner side; and an ignition chamber in communication with saidcombustion chamber.

14. In an internal combustion engine of the type having a cylinder andpiston, the combination of: a combustion chamber separate from theengine cylinder; at first pass age joining said combustion chamber, saidpassage having a length axissubstantially concentric therethrough; asecond passage joining said cylinder, said passage having a length axispassing substantially concentric therethrough, and joining said firstpassage with the length axes of said first and second passages lying inplanes displaced from each other at the juncture of said passages by atleast half the nominal diameter of said first passage and with the anglebetween said axis when projected one upon the other less than 180, saidconfiguration forming a junction between said passages in which saidsecond passage is substantially tangential to said first passage; and anignition chamber in communication with said combus tion chamber.

15. In an internal combustion engine having a cylinder and piston, thecombination of: a combustion chamber separate from the engine cylinder;an ignition chamber in communication with said combustion chamber;passage means from said cylinder to said combustion chamber and saidignition chamber, said passage means having flow dividing means todivide air flowing therethrough from said cylinder into an ignitionchamber charging stream and a combustion chamber charging stream; airdiffusion means in combination with said passage to diffuse saidignition chamber charging stream before entry of said stream into saidignition chamber; and air diffusion means in said combustion chamber todiffuse said combustion chamber charging stream after entry of saidstream into said combustion chamber.

16. In an internal combustion engine of the liquid fuel injection type,having a cylinder and piston, the combination of: a combustion chamberseparate from the engine cylinder; an ignition chamber; a passagejoining said ignition chamber and said combustion chamber, forming aconnecting zone therebetween; passage means from said cylinder to saidconnecting zone; and flow dividing and directing means associated withsaid passage means which divide air entering said connecting zone fromsaid cylinder into a first stream, a second stream and a third stream,and direct said first stream into said combustion chamber and saidsecond stream at least in part into said ignition chamber; said flowdividing and directing means including air diffusion means whichdiffuses said third stream of air and directs said diffused srteam intosaid connecting zone.

17. In an internal combustion engine of the type having a piston andcylinder, the combination of: a combustion chamber separate from saidcylinder; an ignition chamber; a passage joining said ignition chamberand said combustion chamber, forming a connecting zone therebetween;passage means from said cylinder to said connecting zone'arranged todeliver two streams of air from said cylinder to said zone; airdiffusion means in said zone to diffuse said two air streams receivedfrom said cylinder; and flow directing means in said zone to direct saiddiffused air in a plurality of streams toward said combustion chamberand a plurality of streams toward said ignition chamber.

18. In an internal combustion engine of the type hav ing a piston andcylinder, the combination of: a combustion chamber separate from saidcylinder; an ignition chamber; a passage joining said ignition chamberand said combustion chamber, forming a connecting zone therebetween;passage means from said cylinder to said connecting zone to convey airfrom said cylinder to said zone; air diffusion means in said zone todiffuse said air received from said cylinder; and flow division means insaid zone to divide and deliver said diffused air simultaneously to saidcombustion chamber and said ignition chamber.

19. In an internal combustion engine of the liquid fuel injection typehaving a piston and cylinder, the combination of: a combustion chamberseparate from said cylinder; an ignition chamber; a passage joining saidignition chamber and said combustion chamber, forming a connecting zonetherebetween; passage means from said cylinder to said connecting zone,to convey air from said cylinder to said connecting zone; air diffusionmeans in said zone to diffuse a portion of said air and deliver said airto said combustion chamber; liquid fuel receiving means in said zone;air directing means in said zone for forcefully directing an undiffusedportion of said air over said fuel receiving means; and air diffusionmeans in said zone for diffusing another portion of said air anddelivering it to said ignition chamber.

20. In an internal combustion engine of the liquid fuel injection typehaving a cylinder and piston, the combination of: a combustion chamberseparate from the engine cylinder; an ignition chamber; a passagejoining said ignition chamber and said combustion chamber forming aconnecting zone therebetween; fuel vaporization means located in saidconnecting zone; and passage means from said cylinder to said connectingzone to convey air from said cylinder to said Zone and thence in part tosaid combustion chamber and in part to said ignition chamber via, atleast in part, said fuel vaporization means.

21. In an internal combustion engine of the liquid fuel injection typehaving a cylinder and piston, the combination of: a combustion chamberseparate from the engine cylinder; an ignition chamber; a passagejoining said ignition chamber and said combustion chamber forming aconnecting zone therebetween; passage means from said cylinder to saidconnecting zone joining said zone at a point between said ignitionchamber and said combustion chamber; and fuel vaporization means locatedin said connecting Zone at a point between said ignition chamber andsaid point of juncture of said passage means and said connecting zone,whereby air entering said ignition cham bination of:. a.combustion.chamberxseparate from said ber. from. said cylinder flowsatleast in .part; through; said fuel vaporization .meansto convey fuelvapors therefrom means fonthe subsequent engine cycle.

22..v In .an internal combustion engine of :the liquid fuel injectiontype. havinga..p iston; and. cylinder, the comcylinder; an ignitionchamber, a passage, joining said ignition-chamber. and said, combustionchamber, forming a connecting zone therebetween; passage means from saidcylinder:v to; said connecting zone; a. fuel, receiving surfaceinsaidzone; means for'supplyingzliquid fuel to said surface; I and apocket forming a, fuel vaporv collection zone in.saidwconnectingzonelocated between said ignition chamber and. the pointof juncture of the passage from said cylinder.

23.. In an internal combustion engine, oftheliquidfuel injection: type,having a piston andv cylinder, the combination of a separate combustionchamber, communi- .cating with'said cylinder; having anend wall concavein forin; fuel injection means for, depositingliquidfuel on said concavesurface; an ignition chamber; and a passage from said ignition chambenjoining said combustion chamber at a point adjacent said concave surfacesuch that gases flowing from said ignition chamber into said combustionchamber flow against and across said concave surface and said fuel bodythereon.

24. In an internal combustion engine having a piston and cylinder, thecombination of: a combustion chamber separate from said cylinder, saidchamber being substantially a figure of revolution having an end wall inthe form of a spiral ramp with its helix substantially concentric withthe axis of revolution; a passage joining said cylinder and joining saidcombustion chamber tangentially in a plane substantially normal to theaxis of revolution and adjacent the end wall; and an ignition chamber incommunication with said combustion chamber.

25. In an internal combustion engine having a piston and a cylinder, thecombination of: a combustion chamber separate from the engine cylinder;a passage joining said cylinder and said combustion chamber; an ignitionchamber; an intermediate chamber; a passage joining said intermediatechamber and said cylinder; a passage joining said intermediate chamberand said ignition chamber; a passage joining said intermediate chamberand said combustion chamber; and means for injecting fuel into saidintermediate chamber and said combustion chamber.

26. In an internal combustion engine having a piston and cylinder, thecombination of: a combustion chamber separate from said cylinder, saidchamber having an end wall comprised of a spiral ramp and a centralwall, normal to the axis of the helix of said ramp, spaced below thelevel of said ramp, and substantially surrounded by said ramp; a passagejoining said cylinder and joining said combustion chamber tangentiallyin a plane substantially normal to the axis of said helix and adjacentsaid end wall; an ignition chamber; and a passage joining said ignitionchamber and joining said combustion chamber at a level below said rampand adjacent said central wall.

27. In an internal combustion engine having a cylinder and piston, thecombination of: a combustion chamber separate from the engine cylinder;an ignition chamber in communication with said combustion chamber;passage means connecting said engine cylinder to said combustion chamberand adapted to convey air from said cylinder to said combustion chamber;passage means connecting said engine cylinder to said ignition chamberand adapted to convey air from said cylinder to said ignition chamber;and air diffusion means associated with said last named passage meansfor diffusing the air supplied to said ignition chamber to a greaterdegree than the air supplied to said combustion chamber by said firstnamed passage means.

. 2 r I 28. In an.iuternal,combustionengine of the fuelinjection typehaving 5' a, cylinder, and piston, the combination of: a combustionchamber; an ignition chamber; means for, producing fuelvapors;apassagein communication with said fnel vaporproducing-means and said cylinder,and .joined, tangentially; to. said ignition. chamber so that fuelvapors from;said vapor producing means flow in-said ignition chamber ina circulating path about an;,axis-of rotation; a second passage incommunication withsaid cylinder and saidignition chamber, terminating insaid ignition chamber, in; an open channel lying in a plane normal tosaid ,axis of; rotation; and tan-air receiving chamber in communicationwith, saidignition chamber at a point in said channel, whereby air,entering said channel from said cylinder enterssaidair chamber withoutintermixture with said fuelvapors.

29. In an internalcombustion engine-of the itypehaving a cylinderandpiston, the combination of: a combustion chamber separatefrom-theenginecylinder and havingam ndzwall; an gnit n m ap ss e io nsaid: ignitiQn chamber; to said combustion chamberat a point.-adjacent-to said end'wall; and passage meansjoining-said.tcylinden-tosaidcombustion chamber, said passage meansincluding flow directingmeans.arranged'to direct a .portion of. the: airentering saidcombustion chamber to flow-about.- s a idchamben in. a pathspaced away from said end wall and passage to the ignition chamber, andincluding other flow directing means arranged to direct a second portionof the air entering said combustion chamber to flow adjacent said endwall and at least in part into said ignition chamber passage.

30. In an internal combustion engine of the liquid fuel injection typehaving a cylinder and piston, the combination of: a combustion chamber;an ignition chamber; a passage joining said ignition chamber and saidcombustion chamber whereby said ignition chamber is charged with air;fuel injection means for supplying liquid fuel to said ignition chamberin a region remote to the juncture of said passage with said ignitionchamber; and an air receiving chamber joined to said ignition chamber ata point between the juncture of said air passage and said fuel receivingregion.

31. In an internal combustion engine of the liquid fuel injection typehaving a piston and cylinder and a combustion chamber, the combinationof: an ignition chamber, including a fuel receiving wall; cooling meanswhich cool one end of said fuel receiving wall more than the other end;fuel injection means for depositing liquid fuel on the cooler end ofsaid fuel receiving wall and displacing said fuel along said wall towardthe least cooled end; and a passage joining said ignition chamber tosaid combustion chamber.

32. In an internal combustion engine of the liquid fuel injection typehaving a piston and cylinder, the combination of: a combustion chamberin communication with said cylinder; an ignition chamber; passage meansconnecting said ignition chamber to said combustion chamber and saidcylinder arranged in such manner that gases entering said ignitionchamber from said cylinder circulate in said ignition chamber about atleast one axis of rotation; and ignition means in said ignition chamberat a point substantially on said axis of rotation.

33. In an internal combustion engine of the liquid fuel injection type,having a piston and cylinder, the combination of: a combustion chamberin communication with 0 said cylinder; an ignition chamber having achannel extending at least partially around said chamber; a passage fromsaid combustion chamber to said ignition chamber, said passage joiningsaid channel tangentially substantially in the plane of the channel,whereby gases entering said channel are directed to fiow in acirculating path about an axis of rotation; and ignition means in saidignition chamber at a point substantially on said axis of rotation ofsaid gases.

34. In an internal combustion engine of the liquid fuel injection type,having a piston and cylinder, the combination of: a combustion chamberin communication with said cylinder; an ignition chamber having achannel extending at least partially around said chamber; a pas sagefrom said combustion chamber to said ignition chamher, said passagejoining said channel tangentially substantially in the plane of saidchannel, whereby gases entering said channel are directed to flow in acirculating path about an axis; and fuel vaporization means in saidpassage.

35. In an internal combustion engine having a cylinder and piston, thecombination of: a combustion chamber; an ignition chamber substantiallyin the form of a figure of revolution about an axis, with at least oneregion having a larger radial dimension than adjoining portions of saidchamber; passage means in communication with said cylinder and joined tosaid ignition chamber at a point such that air entering said ignitionchamber from said passage flows in a circulating path in the region oflarger radial dimension in a plane substantially normal to said axis ofsaid ignition chamber; means for producing fuel vapors; and a secondpassage in communication with said fuel vapor producing means and joinedto said ignition chamber at a point such that fuel vapors from saidmeans entering said ignition chamber flow in a circulating path aboutsaid axis of revolution in the same direction of rotation as said air insaid region of larger radial dimension, whereby said air and said fuelvapors do not readily intermix.

cylinder; an ignition chamber; a passage joining said ignition chamberand communicating with said combustion chamber whereby said ignitionchamber is charged with fuel vapors; an air receiving space incommunication with said ignition chamber; and a separate passage incommunication with said air space and said cylinder, whereby air issupplied to said air space simultaneously with and independently of thecharging of said ignition chamber with fuel vapors.

37. In an internal combustion engine of the liquid fuel injection typehaving a piston and cylinder, the combination of: a combustion chamberin communication with said cylinder; an ignition chamber; passage meansconnecting said ignition chamber to said combustion chamher and saidcylinder; a liquid fuel injector having a length axis and an orificeadapted to deliver liquid fuel in a stream substantially normal to saidaxis, and with said injector located such that said fuel stream passesdown the length axis of said passage in a direction away from saidignition chamber; and mean for rotating said injector about its lengthaxis whereby the quantity of fuel deposited in said passage may bevaried.

No references cited.

